<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            padding: 0;
            margin: 0;
        }

        ul li {
            list-style: none;
        }

        .menu {
            width: 200px;
            height: auto;
            margin: 100px auto;
        }

        .item {
            cursor: pointer;
        }

        .item>h3 {
            height: 40px;
            line-height: 40px;
            background-color: #7dffe7;
            color: orange;
            padding-left: 10px;
        }

        .item>.itembox {
            width: 100%;
            height: 0px;
            overflow: hidden;
            transition-property: height;
            transition-duration: 1s;
        }

        .item:hover>.itembox {
            height: 90px;
        }
    </style>
</head>

<body>
    <div class="menu">
        <div class="item">
            <h3>市内新闻</h3>
            <div class="itembox">
                <ul>
                    <li>深圳超市肉菜档遭抢</li>
                    <li>深圳超市肉菜档遭抢</li>
                    <li>深圳超市肉菜档遭抢</li>
                    <li>深圳超市肉菜档遭抢</li>
                </ul>
            </div>
        </div>
        <div class="item">
            <h3>省内新闻</h3>
            <div class="itembox">
                <ul>
                    <li>深圳超市肉菜档遭抢</li>
                    <li>深圳超市肉菜档遭抢</li>
                    <li>深圳超市肉菜档遭抢</li>
                    <li>深圳超市肉菜档遭抢</li>
                </ul>
            </div>
        </div>
        <div class="item">
            <h3>国内新闻</h3>
            <div class="itembox">
                <ul>
                    <li>深圳超市肉菜档遭抢</li>
                    <li>深圳超市肉菜档遭抢</li>
                    <li>深圳超市肉菜档遭抢</li>
                    <li>深圳超市肉菜档遭抢</li>
                </ul>
            </div>
        </div>
    </div>
</body>

</html>